Shutoff dampers

ABSTRACT

System for the gastight sealing off and isolating of a section or sections of a flue system, wherein a damper is movable in a guide frame secured to the flue between an open position and a closed position wherein the damper nongastightly closes off a section of the flue. A pressurizable chamber is defined within the damper and extends about at least an outer marginal portion of the damper, with at least that portion of one or both chamber sidewalls adjacent a seating surface of the frame and an edge of the flue adjacent the frame seating surface (when the damper is in the closed position) being yieldable. The introduction of fluid under pressure into the pressurizable chamber when the damper is in the closed position pressurizes the chamber and forces the yieldable sidewall portion or portions into a gastight sealing relationship with at least one of a seating surface of the frame and an edge of the flue adjacent the frame, thereby sealing off and isolating a section or sections of the flue. Consequently workmen may safely perform maintenance and/or repair work on the isolated section of the flue on the downstream side of the damper.

United States Patent [72] Inventor Bartel J. Di Santo Salt Lake City, Utah [21] Appl. No. 835,183

[22] Filed June 20, 1969 [45] Patented Aug. 3, 1971 [73 1 Assignee American Smelting and Refining Company New York, N.Y.

[54] SHUTOFF DAMPERS 5 Claims, 7 Drawing Figs.

52 us. or 251/175, 251/328 511 1111. c1 F161: 3113 1501 FieldofSearch 251/175, 32s,

[56] References Cited UNITED STATES PATENTS 1,957,807 5/1934 Robinson 251/175 x 2,476,711 7/1949 Edwards.... 251/175 2,507,360 5/1950 Wicks..... 251/175 x 2,582,877 1/1952 Mekler... 251/175 2,858,096 10/1958 Warren 251/175 x 2,998,220 8/1961 Grieselhuben 251/175 x 3,206.162 9/1965 Bogot 251/175 x Primary ExaminerClarence R. Gordon Attorneys-Elwood J Schafier and Roger 1. Drew ABSTRACT: System for the gastight sealing ofi and isolating of a section or sections of a flue system, wherein a damper is movable in a guide frame secured to the flue between an open position and a closed position wherein the damper nongastightly closes off a section of the flue. A pressurizable chamber is defined within the damper and extends about at least an outer marginal portion of the damper, with at least that portion of one or both chamber sidewalls adjacent a seating surface of the frame and an edge of the flue adjacent the frame seating surface (when the damper is in the closed position) being yieldable. The introduction of fluid under pressure into the pressurizable chamber when the damper is in the closed position pressurizes the chamber and forces the yieldable sidewall portion or portions into a gastight sealing relationship with at least one of a seating surface of the frame and an edge of the flue adjacent the frame, thereby sealing off and isolating a section or sections of the flue. Consequently workmen may safely perform maintenance and/or repair work on the isolated section of the flue on the downstream side of the damper.

Patented Aug. 3, 1971 3,596,874

5 Sheets-Sheet 1 \NVENTOR 1 BHRTEL J. D: SHNTO BY 3W A TORNEV Patented Aug. 3, 1971 Y 3,596,874

5 Sheets-Sheet 2 T; E. o o 40 o s BRRTEL J. DlfiNTO Patented Aug. 3, 1971 3,596,874

5 Sheets-Sheet 3 PRESSURIZABLE CHAMBER SUPPOR'HNG f u IVEN'TOP Ema-rm. J. D\ SANTQ I av A W ZTTQRNEV Patentepd Aug. 3, 1911 3,596,874

- 5 Sheets-Sheet 4.

lI-IVENTOF? BARTEL J. DI SANTO ATTORNEY -nnnunuunn...

SHUTOFF DAMPERS BACKGROUND OF THE INVENTION 1 Statement of the Invention This invention relates to the fluidtight sealing off and isolating of an enclosed passageway for fluid and more particularly to the gastight sealing off and isolating of a section or sections of a flue system. Additionally this invention is concerned with new and improved shutoff dampers adapted for use in gastightly sealing off and isolating of a section or sections of a flue system.

2. Description of the Prior Art Routine maintenance and necessary repair work on working flue systems usually requires a gastight sealing off of the section or portion of the flue system to be repaired or maintained from the portion of the flue system still in operation. This is very important for protecting the health and safety of the repair workers and also from the standpoint of preventing disadvantageous dilution of process gases or loss of the valuable gases. For instance, in the case of a SO, containing converter gas in a copper smelter which gas is conducted from the converter and ultimately to a sulfuric acid plant by a flue system, the cost of the absorption section of the acid plant is approximately inversely proportional to the S concentration of the gas. Thus if the concentration of SO, in the converter gas is lowered by one-half due to leakage of atmospheric air into the gas through the gaps between a nongas tightly sealing damper and the flue wall edge, the cost of the absorption section is approximately doubled. Further, with the dilution of the S0 containing converter gas with atmospheric air through the gaps, the efficiency of the dust removal from the gas by the Cottrell precipitators is appreciably reduced. The 80 containing converter gas also contains entrained dust, and it is important the dust be removed prior to introduction of the gas into the absorbers of the sulfuric acid plant. However for good efficiency in the dust removal by the precipitators, the time the gas is in the electrical field of the precipitators is critical. When the gas is diluted appreciably with the air, its volume and velocity is increased and the time the gas is in the electrical field of the precipitator is appreciably reduced. Consequently the efficiency of the dust removal by the precipitators is appreciably lowered.

Further, in the bag house employed in connection with a zinc fuming plant, the more leakage of atmospheric air into the flue gas the larger the bag house is required to be. And the larger the bag house is required to be, the more power that is required to drive the fans for filtering the gas through the bags.

In the past, flues or flue sections have been gastightly sealed off from other parts of the flue system by means of a plate damper, with caulking of the gaps between the damper and the flue wall with asbestos rope followed by the mud-up of the entire outer edges of the damper. Flue sections have also been gastightly sealed off heretofore from other sections or flues of the flue system, by the construction of a masonry barrier wall in the flue close by the damper. Although these prior art practices are satisfactory in certain respects, they are slow and tend to be quite inefficient. Further the entire practise or operation is required to be done in the interior of the flue.

OBJECTS OF THE INVENTION A principal object of this invention is to provide a system and method for the fast and efficient fluidtight sealing off and isolating of a section or sections of an enclosed passageway or flue system.

Another object is to provide a system and method for the gastight sealing off and isolating of a section or sections of a flue system, which may be carried out entirely from the outside of the flue.

Additional objects and advantages will be readily appatent as the invention is hereinafter described in more detail.

SUMMARY OF THE INVENTION In accordance with the present invention, the system for the fluidtight sealing off of the enclosed passageway for fluid comprises the enclosed passageway, for instance a flue, a fixed guide frame secured in or to the enclosed passageway, an open passage in the guide frame, and a closure member such as a damper or valve, movable in the guide frame between an open position and a closed position wherein the closure member closes the open passage and closes off a section or sections of the flue. The closure member comprises a pressurizable chamber defined therewithin and extending about at least an outer marginal portion of the closure member, the pressurizable chamber being defined by spaced apart sidewalls and spaced apart end walls with at least that portion of at least one of the sidewalls of the chamber adjacent a seating surface of the frame and an edge of the flue adjacentthe frame seating surface (when the closure member is in the closed position) being yieldable. Means are provided for introducing fluid under pressure into the pressurizable chamber when the closure member. is in the closed position, thereby to pressurize the chamber and force or press the yieldable sidewall portion into a fluidtight sealing relationship with the sealing surface of the frame and/or the edge of the enclosed passageway adjacent the frame. Means are provided for releasing the pressure in the pressurizable chamber when it is desired to move the closure member to an open position. The system constitutes a considerable improvement in the fluidtight sealing off and isolating of a section or sections of a flue system for enabling the safe maintenance and/or repair work on the isolated section by workmen, from the standpoint of being considerably faster and more efficient than the prior art caulking and mudding of the gaps or cracks between the damper and flue wall or the prior art erectionof the masonry barrier wall, and also by enabling the entire closing and sealing operation to be conducted from the outside of the flue.

The enclosed passageway, for instance a flue, is fluidtightly sealed ofl', in accordance with this invention, by moving the closure member from an open position to a closed position wherein the closure member closes off a section of the flue. Fluid under pressure is then introduced into the pressurizable chamber of the closure member to pressurize the chamber and force the yieldable side wallportion or portions thereof into a fluidtight sealing relationship with a seating surface of the frame of the closure member and/or an edge of the flue adjacent the frame.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS Reference is now made to the accompanying drawings wherein:

FIG. 1 is a cross-sectional view through a shutoff damper of this invention and a portion of a flue system.

FIG. 2 is a section taken on line 2-2 of FIG. 1.

FIG. 3 is a isometric fragmentary sectional view through the marginal pressurizable chamber portion of the damper and the guide frame of this invention and also showing a portion of a flue.

FIG. 4 is a section taken on line 4-4 of FIG. 1.

FIG. 5 is a cross-sectional view through a shutoff damper in accordance with another embodiment of this invention.

FIG. 6 is a front elevational view partially broken away of the damper of FIGS. 1 and 2 which has been removed from its hoist and support frame; and

FIG. 7 is a front elevational view partially broken away of another embodiment of a damper of this invention.

DETAILED DESCRIPTION Referring to FIG. I. flue or duct 10 for a gas, for instance a dust-burdened SO, containing converter gas in a copper smelter, isconnected to flue I1 extending at a right angle to flue 10 by being bolted to flue reducing section 12 at flange connection 13. As shown in FIGS. 1-3, guide frame 14 composed of upper structural members 15, lower structural members l6, and side structural members 17 at each side of the flue, is secured in or to the flue and about the flue by welding. As shown, the upper and lower structural members 15 and 16 are H channel members and the side structural members 17 of the frame are channel members. An open passage 19, shown closed in FIGS. 1 and 3 by damper 20, is provided in and defined by guide frame 14. An I beam 18 shown in FIG. 1 serves to support a portion of flue 11, and brace member 190 shown in FIG. 3 is welded to channel 17 and to the flue wall.

Damper or valve 20, shown in FIGS. 1-3 and 6, is composed of spaced apart, substantially parallel ferrous metal plates 21 and 22. Channel members 23 are welded to the op' posing plates 21 and 22 of the damper to form supporting frame 24 shown in FIG. 2. Pressurizable chamber 25 is defined solely or entirely within closure member or damper and extends continuously about an outer marginal portion of damper 20. Pressurizable chamber is defined by spaced apart sidewalls 25a and 25b and spaced apart end walls 26 and 27 respectively. As shown in FIGS. 1 and 3, plates 21 and 22 of the damper 20 also serve as the sidewalls of the pressurizable chamber 25.

Sidewall 25a of pressurizable chamber 25 is relatively thin and yieldable, as shown in FIG. 3, to fluid pressure and preferably only in that portion of sidewall 25a adjacent the flat, smooth seat or seating surface 28 of channel 17 of frame 14 and adjacent smooth edge 29 of the wall 30 of flue 10. Although sidewall member 25b of chamber 20 can also be yieldable to fluid pressure and preferably only in the portion thereof corresponding to that portion of sidewall 25a disclosed immediately above, sidewall 25b is preferably relatively thicker, rigid and substantially nonyieldable to the fluid pressure in pressurizable chamber 25. Preferably spaced apart rods 31 are secured to sidewalls 25a and 25b, for instance by welding or riveting, in those portions of sidewalls 25a and 25b nonadjacent or remote to seat 28 and wall edge 29 of the flue, to brace and prevent outward bowing of wall 250, or of walls 250 and 25b when both are yieldable, in those portions thereof where it is not desired.

End walls 26 and 27 are expansible and are of thin ferrous metal, preferably thin steel strip or sheet, and are fluidtight or gastightly joined to ferrous metal sidewalls 25a and 25b. As shown, end wall members 26 and 27 are bent or partially folded inwardly of the pressurizable chamber they aid in definingl Alternatively, expansible walls 26 and 27 can be fabricated of an elastomer as exemplified by a synthetic rubber, e.g. rubbery copolymers of butadiene and styrene marketable as "GR-S-AC" rubbers. Natural rubbers are also utilizable for fabricating expansible end walls 26 and 27. Any expansible material including elastomers can be utilized for fabricating expansible end walls 26 and 27 so long as the expansible material is capable of withstanding the temperature and other conditions to be encountered in operation of the flue or enclosed passageway. Thus when high temperatures are encountered in the flue system, the expansible end walls 26 and 27 are fabricated of an expansible material capable of withstanding the high temperature, for instance of thin steel. However when high temperatures and/or other conditions nondetrimental to the use of other expansible materials are not to be encountered, for instance in the case of flues with substantially nonreactive gases and/or gases at low temperature, the expansible material other than the thin ferrous metal can be employed, if desired, for fabricating expansible end walls 26 and 27. Any source of pressurized fluid is utilizable herein for source 32, shown in FIG. 2, for example a compressor when air or another gas is the fluid, and a hydraulic liquid reservoir and pump when the fluid is a liquid, e.g. oil, water or another hydraulic liquid.

Hoist and support frame 33 shown in FIGS. 1, 2 and 4 comprises end channel members 34 and 35, shown in FIG. 4, and side plates 36 and 37 gastightly welded to channel members 34 and 35. Plates 34a and a are gastightly welded to the ends of channel members 34 and 35. Hoist 38, shown in FIG. 2, includes sheaves 39, 40 and 41 and cables 42 and 43 attached to the upper portion of damper 20 with the aid of loops 42a and 43a secured to the damper.

Source 32 of pressurized fluid is connected by valved conduit 45 equipped with three way valve 46 to inlet 47 in the upper portion 48 of hoist and support frame 33. Inlet 47 is in turn connected to flexible hose 49 which in turn is connected to inlet 51 for fluid pressure of pressurizable chamber 25 of damper 20. As shown in FIG. 2, when damper 20 is in its lowered closed position, flexible hose 49 is moved downwardly within hoist and support frame 33 with the damper. When damper 20 is in a raised open position as indicated by dotted line 52, flexible hose 49 is folded in a narrow storage space 53 in hoist and support frame 33 and defined by the top of damper 20 and the top of frame 33. To provide this storage space 53 for hose 49, the length of the guide and support frame 33 is materially greater than the length of damper 20.

The damper of this invention can be of any desired shape or configuration, with its shape usually corresponding to that of the cross-sectional shape or configuration of the particular flue or enclosed passageway in which it is employed. Thus the dampers herein can be, for example, rectangular, circular, square, triangular in shape or configuration, or generally of such configuration, or of another desired shape or configuration. The dampers of FIGS. 1-3 and 5 and 6 are rectangular in configuration whereas the damper of FIG. 7 is circular in configuration. The dimensions of the damper or valve herein will usually approximate the dimensions of the flue section which it is desired to gastightly seal off taken on a plane which is perpendicular to the principle axis of the flue or enclosed passageway, with the dimensions of the damper usually being somewhat larger than those of the flue section desired to be gastightly sealed off and such that the expansible sidewall portion or portions of its pressurizable chamber will press against a seat or seating surface on the guide frame for the damper and/or an edge of the flue or passageway when the pressurizable chamber is fluid pressurized. In the circular damper of FIG. 7, the channel members 23 utilized for the supporting frame 24 are bent or formed in arcuate or curved shape, and the expansible walls 26 and 27 of the pressurizable chamber 25 are of circular shape.

The typical dimensions of the damper of this invention when employed in a flue system leading from a converter in a copper smelter, such as in FIG. 1, are a height of typically 10 feet 6 inches, width of typically 8 feet 6 inches, and thickness of typically 4 inches with a typical length of the pressurizable chamber between the expansible end walls thereof and before fluid pressurization thereof being about 18 inches.

In the embodiment of FIG. 5, the damper 55 is hollow and pressurizable chamber 56 extends throughout substantially the entire length and width of the enclosed area within the damper. Yieldable sidewall 57, on the upstream side of the damper, is fabricated of a relatively thin or light steel sheet, arid nonyieldable or substantially nonyieldable sidewall 58 is fabricated of relatively thick or heavy steel sheet. Expansible end walls 59 and 60 of any suitable expansible material as previously disclosed herein are at opposite ends of damper 55 and fluidtight or gastightly joined to its sidewalls 57 and 58. As shown, end walls 59 and 60 are bent or folded inwardly to form a pleat or fold. Rods 61 secured to sidewalls 57 and 58 stiffen the middle portion of the relatively thin sheet of sidewall 57. End plate 62 is bolted to the ends of the channel members 63 to enable, by removal of plate 62, the removal when desired of any accumulated dust from space 51. Angle members are designated at 67. The remainder of the damper as well as the hoist and support frame of the embodiment of FIG. 5 is substantially identical to that of FIGS. 1-3.

In operation, the shutoff damper or valve 20 of FIGS. 1-4 is lowered in place in guide frame 14 by hoist 38, shown in FIG. 2, to nonfluid tightly close the open passage 19 of flue 10. Pressurized fluid from source 32, for instance compressed air from a compressor, is then introduced into the pressurizable chamber 25 of damper through valved conduit 45, inlet 47, flexible hose 49 and inlet 51, shown in FIG. 2, three way valve 46 being opened prior to the passage of the pressurized fluid through conduit 33. Due to the incoming pressurized fluid, expansible end walls 26- and 27 of chamber 25, shown in FIGS. 1 and 3, are forced outwardly a short distance from their at rest dotted line positions 26a and 27a and chamber is pressurized or inflated. When chamber 25 is pressurized to the desired extent, valve 46 is closed so as to maintain chamber 25 pressurized. Due to the fluid pressure in pressurized chamber 25, at least yieldable sidewall 25a and also sidewall 25b when yieldable are pressed or forced outwardly into fluidtight or gastight sealing relationship against flat, smooth seat or surface 28 or channel 17 of the frame 14 and, if desired, also with edge 29 of the flue wall or walls 30. If edge or edges 29 of the flue wall or walls 30 are to be utilized herein as fluidtight or gastight sealing surfaces, the flue wall edge or edges, shown in FIG. 3, will be extended to be flush or virtually flush with seat or surface 28 or channel or channels 17. The flue section or sections on the downstream side of closure member 20 are thereby gastightly sealed off from the flue section or sections and equipment connected thereto on the upstream side of damper 20. i

To move the damper to an open position to thereby open the flue, the pressure is released from its pressurized chamber 25 by opening three-way valve 46. Consequently yieldable sidewall 25a and also sidewall 251;, if yieldable, move inwardly and out of fluidtight sealing contact with seat 28 of channel or channels 17 and also out of fluidtight sealing contact with edge 29 of flue wall or walls 30 if previously forced into fluidtight sealing contact with flue wall edge 29, whereby damper 20 can be lifted to the open position by means of the hoist 38.

The valve or damper 55 of the FIG. 5 embodiment is operated in substantially identical manner as that of the embodiment of FIGS. 1-3 except that in the damper of FIG. 5, with the damper in the lowered, closed position, end walls 59 and 60 of the hollow damper .are forced outwardly an appreciable distance due to the incoming fluid pressure and the pressurizable chamber 56 is pressurized. Due to the fluid pressure in chamber 56, yieldable sidewall 57 is forced or pressed outwardly in fluidtight or gastight sealing relationship against the smooth, flat edge 64 of the flue sidewall 65, of the frame. Consequently the flue section on the downstream side of damper 55 is fluidtightly sealed off from the flue section and any equipment connected thereto upstream of damper 55.

While certain novel features of the invention have been disclosed herein and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes may be made by those skilled in the art without departing from the spirit of the invention.

lclaim:

1. A system for the gastight sealing off and isolating of a flue for a high-temperature gas, which comprises:

a. a flue for the high-temperature gas;

b. a guide frame secured to the flue;

c. an open passage in the guide frame;

of at least one sidewall adjacent an immovable seating surface of the frame and an edge of the flue adjacent the frame seating surface when the damper is in the closed position being yieldable and at least one of said end walls being expansible, the pressurizable chamber sidewalls and end walls beingfabricated of a ferrous metal; f. means for introducing fluid under pressure into the pressurizable chamber when the damper is in the closed position thereby to pressurize the chamber and force the yieldable flat sidewall portion into a gastight sealing relationship with at least one of the immovable seating surface of the frame and the edge of the flue adjacent the frame, and

3. means for releasing the pressure in the pressurized chamber.

2. A system for the gastight sealing off and isolating of a flue for a dust-containing, high-temperature, SO containing converter gas in a copper smelter, which comprises:

a. a flue for the dust-containing, high-temperature SO, containing converter gas;

b. a guide frame secured to and about the flue;

c. an open passage in the guide frame;

d. a damper movable in the guide frame between an open position and a closed position closing the open passage and closing off a section of the flue;

e. the damper comprising a pressurizable chamber defined therewithin and extending continuously about only an outer marginal portion of the damper, the pressurizable chamber being defined by spaced apart flat sidewalls which also serve as portions of the walls of the damper and spaced apart end walls with at least one of said sidewalls being yieldable and both of said end walls being expansible, the pressurizable chamber sidewalls and end walls being fabricated of a ferrous metal; means for introducing fluid under pressure into the pressurizable chamber when the damper is in the closed position thereby to pressurize .the chamber and force the yieldable flat sidewall into a gastight sealing relationship with at least one of an immovable seating surface of the frame and an edge of the flue adjacent the frame, and

g. means for releasing the pressure in the pressurizable chamber.

3. The system of claim 2 wherein the ferrous metal of the expansible end walls is steel.

4. The system of claim 2 wherein the pressurized fluid-introducing means is a pressurized gas-introducing means.

5. The system of claim 4 wherein the pressurized gas-introducing means is an air compressor.

H050 UNITED STATES PATENT OFFICE 569 CERTIFICATE OF CORRECTION Patent 3.596.874 Dated Au ust 3. 1971 Inventor(s) Bartel J. DiSanto It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

T Column 5 line 15 "or" should read of line 20, 1

after "28" and before "channel" "or" should read --of--.

Signed and sealed this 11th day of January 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK At testing Officer Acting Commissioner of Patents 

1. A system for the gastight sealing off and isolating of a flue for a high-temperature gas, which comprises: a. a flue for the high-temperature gas; b. a guide frame secured to the flue; c. an open passage in the guide frame; d. a damper movable in the guide frame between an open position and a closed position closing the open passage and closing off a section of the flue; e. the damper comprising a pressurizable chamber defined therewithin and extending continuously about only an outer marginal portion of the damper, the pressurizable chamber being defined by spaced apart flat sidewalls which also serve as portions of the walls of the damper and spaced apart end walls with at least that flat portion of at least one sidewall adjacent an immovable seating surface of the frame and an edge of the flue adjacent the frame seating surface when the damper is in the closed position being yieldable and at least one of said end walls being expansible, the pressurizable chamber sidewalls and end walls being fabricated of a ferrous metal; f. means for introducing fluid under pressure into the pressurizable chamber when the damper is in the closed position thereby to pressurize the chamber and force the yieldable flat sidewall portion into a gastight sealing relationship with at least one of the immovable seating surface of the frame and the edge of the flue adjacent the frame, and g. means for releasing the pressure in the pressurized chamber.
 2. A system for the gastight sealing off and isolating of a flue for a dust-containing, high-temperature, SO2 containing converter gas in a copper smelter, which comprises: a. a flue for the dust-containing, high-temperature SO2 containing converter gas; b. a guide frame secured to and about the flue; c. an open passage in the guide frame; d. a damper movable in the guide frame between an open position and a closed position closing the open passage and closing off a section of the flue; e. the damper comprising a pressurizable chamber defined therewithin and extending continuously about only an outer marginal portion of the damper, the pressurizable chamber being defined by spaced apart flat sidewalls which also serve as portions of the walls of the damper and spaced apart end walls with at least one of said sidewalls being yieldable and both of said end walls being expansible, the pressurizable chamber sidewalls and enD walls being fabricated of a ferrous metal; f. means for introducing fluid under pressure into the pressurizable chamber when the damper is in the closed position thereby to pressurize the chamber and force the yieldable flat sidewall into a gastight sealing relationship with at least one of an immovable seating surface of the frame and an edge of the flue adjacent the frame, and g. means for releasing the pressure in the pressurizable chamber.
 3. The system of claim 2 wherein the ferrous metal of the expansible end walls is steel.
 4. The system of claim 2 wherein the pressurized fluid-introducing means is a pressurized gas-introducing means.
 5. The system of claim 4 wherein the pressurized gas-introducing means is an air compressor. 